The present invention relates to an automatic guided vehicle for carrying goods along a predetermined travel path and a method for controlling the travel of the automatic guided vehicle.
A conventional automatic guided vehicle travels along a predetermined travel path while a means for detecting the distance between the vehicle and an object detects whether or not an object is present approximately 2 m forward of the vehicle. If no object is detected, the vehicle travels at a predetermined speed of approximately 60 m/min. If any object is detected, the vehicle speed is reduced or the vehicle is stopped.
According to the known control program for controlling the travel of a plurality of vehicles along travel paths leading to a plurality of start places and destinations, each automatic guided vehicle starts from its start place and travels along a common travel path until it arrives at its destination.
According to such a control method, when many automatic guided vehicles travel along the travel path, the vehicles travel as chained together with a distance between adjacent vehicles of approximately 2 m. Accordingly, the number of vehicles which can travel along the entire path is small.
Additionally, when a person walks across the travel path with the vehicle chained together as described above, an automatic guided vehicle travelling at the head of the vehicles immediately detects the person, thus reducing its speed or stopping. Consequently, succeeding vehicles sequentially reduce their speed or stop. Therefore, when the head vehicle increases its speed or starts up to a predetermined speed, it takes much time for all vehicles to increase the speeds thereof up to the predetermined speeds or to start. Thus, it is difficult for vehicles to travel smoothly.